| Thekchok Dorje | Thekchok Dorje |
| Thelema | Thelema |
| Thelonious Monk | Thelonious Monk |
| Thematic Apperception Test | Thematic Apperception Test |
| Themba Dlamini | Themba Dlamini |
| Themistoklis Sophoulis | Themistoklis Sophoulis |
| Theo Angelopoulos | Theodoros Angelopoulos |
| Theo de Raadt | Theo de Raadt |
| Theo van Doesburg | Theo van Doesburg |
| Theo van Gogh | Theo van Gogh |
| Theo Walcott | Theo Walcott |
| Theobald Boehm | Theobald Boehm |
| Theobald von Bethmann Hollweg | Theobald von Bethmann Hollweg |
| Theobald Wolfe Tone | Theobald Wolfe Tone |
| Theobroma | Theobroma |
| Theodor Billroth | Theodor Billroth |
| Theodor Dannecker | Theodor Dannecker |
| Theodor Fontane | Theodor Fontane |
| Theodor Gustav Heinrich Eimer | Theodor Eimer |
| Theodor Hendrik van de Velde | Theodoor Hendrik van de Velde |
| Theodor Hermann Meynert | Theodor Meynert |
| Theodor Herzl | Theodor Herzl |
| Theodor Heuss | Theodor Heuss |
| Theodor Kullak | Theodor Kullak |
| Theodor Ludwig Wilhelm Bischoff | Theodor Ludwig Wilhelm Bischoff |
| Theodor Morell | Theodor Morell |
| Theodor Schwann | Theodor Schwann |
| Theodor Storm | Theodor Storm |
| Theodor Svedberg | Theodor Svedberg |
| Theodor Zwinger | Theodor Zwinger |
| Theodore Bibliander | Theodore Bibliander |
| Theodore Dreiser | Theodore Dreiser |
| Theodore Long | Theodore Long |
| Theodore Nicholas Gill | Theodore Gill |
| Theodore Roosevelt | Theodore Roosevelt |
| Theodore Schultz | Theodore Schultz |
| Theodore Sturgeon | Theodore Sturgeon |
| Theodore Taylor | Ted Taylor |
| Theodore von Kármán | Theodore von Kármán |
| Theodore William Richards | Theodore William Richards |
| Theodoros Deligiannis | Theodoros Deligiannis |
| Theodoros Pangalos | Theodoros Pangalos |
| Theodosius Dobzhansky | Theodosius Dobzhansky |
| Theofiel Middelkamp | Theo Middelkamp |
| Theofánis Ghékas | Theofanis Gekas |
| Theophilus Khumalo | Doctor Khumalo |
| Theophrastaceae | Theophrastaceae |
| Theora | Theora |
| Theoreme de Poincare | Poincare theorem |
| Theoreme de Von Zeipel | Von Zeipel theorem |
| Theorie | Theorie |
| Theorie de la boule de neige | Dirty snowball theory |
| Theorie de la dynamo | Dynamo theory |
| Theorie de la pulsation | Pulsation theory |
| Theorie de Opik | Opik theory |
| Theorie des perturbations | Perturbation theory |
| Theorie du mouvement de la lu | Lunar theory |
| Theorie du potentiel | Potential theory |
| Theorie electromagnetique | Electromagnetic theory |
| Theorie orbitale | Orbital theory |
| Theorie planetaire | Planetary theory |
| Theorie quantique des champs | Quantum field theory |
| Theotokos | Theotokos |
| Thera britannica | Spruce Carpet |
| Thera juniperata | Juniper Carpet |
| Theraphosa | Theraphosa |
| Theraphosa blondi | Goliath birdeater |
| Therapsida | Therapsida |
| There Is Nothing Left to Lose | There Is Nothing Left to Lose |
| Therese Borssen | Therese Borssén |
| Theridiidae | Tangle web spider |
| Theriodontia | Theriodont |
| Therissos | Theriso |
| Theristicus caudatus | Buff-necked Ibis |
| Therizinosaurus | Therizinosaurus |
| Thermal Design Power | Thermal Design Power |
| Thermaltake Technology | Thermaltake |
| Thermes de Caracalla | Baths of Caracalla |
| Thermes de Dioclétien | Baths of Diocletian |
| Thermes de Trajan | Baths of Trajan |
| thermgiste | thermologist |
| thermidor | Thermidor |
| thermique | thermal |
| thermistance | thermistor |
| Thermo | Tue |
| Thermoacoustique | Thermoacoustic hot air engine |
| Thermochromie | Thermochromism |
| thermocline | thermocline |
| Thermocouple | Thermo-couple |
| thermodurcissable | thermosetting |
| thermodynamique | thermodynamics |
| Thermodynamique des trous noirs | Black hole thermodynamics |
| Thermokarst | Thermokarst |
| Thermoluminescence | Thermoluminescence dating |
| thermomètre | thermometer |
| thermomètre médical | clinical thermometer |
| thermonucléaire | thermonuclear |
| thermoplastique | thermoplastic |
| thermopompe | heat pump |
| Thermopyles | Thermopylae |
| thermorégulation | thermoregulation |
| thermorésistant | heat-resistant |
| thermos | thermos |
| Thermoscope | Galileo thermometer |
| thermosphère | thermosphere |
| thermostat | thermostat |
| thermotropisme | thermotropism |
| thermoélectrique | thermoelectric |
| thermoïonique | thermionic |
| Theropoda | Theropoda |
| Thersandre | Thersander |
| Thersite | Thersites |
| Therwil | Therwil |
| Thesmophories | Thesmophoria |
| Thespies | Thespiae |
| Thespis | Thespis |
| Thesprotie | Thesprotia |
| Thessalie | Thessaly |
| Thessalien | Thessalian |
| thessalonicien | Thessalonian |
| Thessaloniciens | Thessalonians |
| Thessaloniki | Thessaloniki |
| Thessaloniké | Thessalonica of Macedon |
| Thessalonique | Thessaloniki |
| Theta Cassiopeiae | Theta Cassiopeiae |
| Theta Centauri | Theta Centauri |
| Theta Eridani | Theta Eridani |
| Theta Pegasi | Theta Pegasi |
| Theta Scorpii | Theta Scorpii |
| Thetford | Thetford |
| Theys Eluay | Theys Eluay |
| Theódoros Kolokotrónis | Theodoros Kolokotronis |
| Theódoros Papaloukás | Theodoros Papaloukas |
| Theódoros Zagorákis | Theodoros Zagorakis |
| Thiago Motta | Thiago Motta |
| thiamine | thiamine |
